Failure characteristics and control mechanism of shallow buried hard coal roadway

Under the influence of high overburden stress, the block falling phenomenon of two sides of hard coal roadway is serious. In order to improve the safety and stability of the roadway, typical hard coal roadway in Yubei area is selected as the background. Combined with field measurement, theoretical analysis and numerical calculation, the failure characteristics and control mechanism of roadway coal are analyzed. Results show that the inner circumferential fractures are developed in the two sides of hard coal roadway, and the fracture spacing is about 0.5-1.0 m. The closer the roadway is, the higher the degree of fracture development is. Under the influence of overburden stress, the deformation of the coal plate fracture structure （0．017 ｍ） is more than twice that of the material（0．007 7 ｍ）, and the deformation of the coal seam in the roadway is mainly structural deformation. The greater the prestress of the bolt is, the stronger the control ability of the cracked coal is. The field measurement shows that the deformation of coal body in the two sides is reduced by more than 90% after increasing the support strength and preload.